/*
A JavaScript implementation of the SHA512 Secure Hash Algorithm,
as defined in FIPS PUB 180-2.
http://csrc.nist.gov/CryptoToolkit/tkhash.html

Bits and pieces of Paul Johnson's JavaScript SHA1 library
were used. The original library can be found at:
http://pajhome.org.uk/crypt/md5
*/


//Configurable variables. You may need to tweak these to be compatible with
//the server-side, but the defaults work in most cases.

var hexcase = 1;  /* hex output format. 0 - lowercase; 1 - uppercase        */
var b64pad  = "="; /* base-64 pad character. "=" for strict RFC compliance   */
var chrsz = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */

//These are the functions you'll usually want to call
//They take string arguments and return either hex or base-64 encoded strings
function hex_sha512(s){return binb2hex(core_sha512(str2binb(s),s.length * chrsz));}
function b64_sha512(s){return binb2b64(core_sha512(str2binb(s),s.length * chrsz));}
function str_sha512(s){return binb2str(core_sha512(str2binb(s),s.length * chrsz));}


var sha512_k;
//Calculate the SHA-512 of an array of big-endian dwords, and a bit length
function core_sha512(x, len)
{
  if(sha512_k == undefined)
  {
    //SHA512 constants
    sha512_k = new Array(
new int64(0x428a2f98, -685199838), new int64(0x71374491, 0x23ef65cd), new int64(-1245643825, -330482897), new int64(-373957723, -2121671748), 
new int64(0x3956c25b, -213338824), new int64(0x59f111f1, -1241133031), new int64(-1841331548, -1357295717), new int64(-1424204075, -630357736), 
new int64(-670586216, -1560083902), new int64(0x12835b01, 0x45706fbe), new int64(0x243185be, 0x4ee4b28c), new int64(0x550c7dc3, -704662302), 
new int64(0x72be5d74, -226784913), new int64(-2132889090, 0x3b1696b1), new int64(-1680079193, 0x25c71235), new int64(-1046744716, -815192428), 
new int64(-459576895, -1628353838), new int64(-272742522, 0x384f25e3), new int64(0xfc19dc6, -1953704523), new int64(0x240ca1cc, 0x77ac9c65), 
new int64(0x2de92c6f, 0x592b0275), new int64(0x4a7484aa, 0x6ea6e483), new int64(0x5cb0a9dc, -1119749164), new int64(0x76f988da, -2096016459), 
new int64(-1740746414, -295247957), new int64(-1473132947, 0x2db43210), new int64(-1341970488, -1728372417), new int64(-1084653625, -1091629340), 
new int64(-958395405, 0x3da88fc2), new int64(-710438585, -1828018395), new int64(0x6ca6351, -536640913), new int64(0x14292967, 0xa0e6e70), 
new int64(0x27b70a85, 0x46d22ffc), new int64(0x2e1b2138, 0x5c26c926), new int64(0x4d2c6dfc, 0x5ac42aed), new int64(0x53380d13, -1651133473), 
new int64(0x650a7354, -1951439906), new int64(0x766a0abb, 0x3c77b2a8), new int64(-2117940946, 0x47edaee6), new int64(-1838011259, 0x1482353b), 
new int64(-1564481375, 0x4cf10364), new int64(-1474664885, -1136513023), new int64(-1035236496, -789014639), new int64(-949202525, 0x654be30), 
new int64(-778901479, -688958952), new int64(-694614492, 0x5565a910), new int64(-200395387, 0x5771202a), new int64(0x106aa070, 0x32bbd1b8), 
new int64(0x19a4c116, -1194143544), new int64(0x1e376c08, 0x5141ab53), new int64(0x2748774c, -544281703), new int64(0x34b0bcb5, -509917016), 
new int64(0x391c0cb3, -976659869), new int64(0x4ed8aa4a, -482243893), new int64(0x5b9cca4f, 0x7763e373), new int64(0x682e6ff3, -692930397), 
new int64(0x748f82ee, 0x5defb2fc), new int64(0x78a5636f, 0x43172f60), new int64(-2067236844, -1578062990), new int64(-1933114872, 0x1a6439ec), 
new int64(-1866530822, 0x23631e28), new int64(-1538233109, -561857047), new int64(-1090935817, -1295615723), new int64(-965641998, -479046869), 
new int64(-903397682, -366583396), new int64(-779700025, 0x21c0c207), new int64(-354779690, -840897762), new int64(-176337025, -294727304), 
new int64(0x6f067aa, 0x72176fba), new int64(0xa637dc5, -1563912026), new int64(0x113f9804, -1090974290), new int64(0x1b710b35, 0x131c471b), 
new int64(0x28db77f5, 0x23047d84), new int64(0x32caab7b, 0x40c72493), new int64(0x3c9ebe0a, 0x15c9bebc), new int64(0x431d67c4, -1676669620), 
new int64(0x4cc5d4be, -885112138), new int64(0x597f299c, -60457430), new int64(0x5fcb6fab, 0x3ad6faec), new int64(0x6c44198c, 0x4a475817));
  }

  //Initial hash values
  var H = new Array(
new int64(0x6a09e667, -205731576),
new int64(-1150833019, -2067093701),
new int64(0x3c6ef372, -23791573),
new int64(-1521486534, 0x5f1d36f1),
new int64(0x510e527f, -1377402159),
new int64(-1694144372, 0x2b3e6c1f),
new int64(0x1f83d9ab, -79577749),
new int64(0x5be0cd19, 0x137e2179));

  var T1 = new int64(0, 0),
    T2 = new int64(0, 0),
    a = new int64(0,0),
    b = new int64(0,0),
    c = new int64(0,0),
    d = new int64(0,0),
    e = new int64(0,0),
    f = new int64(0,0),
    g = new int64(0,0),
    h = new int64(0,0),
    //Temporary variables not specified by the document
    s0 = new int64(0, 0),
    s1 = new int64(0, 0),
    Ch = new int64(0, 0),
    Maj = new int64(0, 0),
    r1 = new int64(0, 0),
    r2 = new int64(0, 0),
    r3 = new int64(0, 0);
  var j, i;
  var W = new Array(80);
  for(i=0; i<80; i++)
    W[i] = new int64(0, 0);
  
  // append padding to the source string. The format is described in the FIPS.
  x[len >> 5] |= 0x80 << (24 - (len & 0x1f));
  x[((len + 128 >> 10)<< 5) + 31] = len;
  
  for(i = 0; i<x.length; i+=32) //32 dwords is the block size
  {
    int64copy(a, H[0]);
    int64copy(b, H[1]);
    int64copy(c, H[2]);
    int64copy(d, H[3]);
    int64copy(e, H[4]);
    int64copy(f, H[5]);
    int64copy(g, H[6]);
    int64copy(h, H[7]);
    
    for(j=0; j<16; j++)
    {
        W[j].h = x[i + 2*j];
        W[j].l = x[i + 2*j + 1];
    }
        
    for(j=16; j<80; j++)
    {
      //sigma1
      int64rrot(r1, W[j-2], 19);
      int64revrrot(r2, W[j-2], 29);
      int64shr(r3, W[j-2], 6);
      s1.l = r1.l ^ r2.l ^ r3.l;
      s1.h = r1.h ^ r2.h ^ r3.h;
      //sigma0
      int64rrot(r1, W[j-15], 1);
      int64rrot(r2, W[j-15], 8);
      int64shr(r3, W[j-15], 7);
      s0.l = r1.l ^ r2.l ^ r3.l;
      s0.h = r1.h ^ r2.h ^ r3.h;
      
      int64add4(W[j], s1, W[j-7], s0, W[j-16]);
    }
  
    for(j = 0; j < 80; j++)
    {
      //Ch
      Ch.l = (e.l & f.l) ^ (~e.l & g.l);
      Ch.h = (e.h & f.h) ^ (~e.h & g.h);
      
      //Sigma1
      int64rrot(r1, e, 14);
      int64rrot(r2, e, 18);
      int64revrrot(r3, e, 9);
      s1.l = r1.l ^ r2.l ^ r3.l;
      s1.h = r1.h ^ r2.h ^ r3.h;
      
      //Sigma0
      int64rrot(r1, a, 28);
      int64revrrot(r2, a, 2);
      int64revrrot(r3, a, 7);
      s0.l = r1.l ^ r2.l ^ r3.l;
      s0.h = r1.h ^ r2.h ^ r3.h;
      
      //Maj
      Maj.l = (a.l & b.l) ^ (a.l & c.l) ^ (b.l & c.l);
      Maj.h = (a.h & b.h) ^ (a.h & c.h) ^ (b.h & c.h);
      
      int64add5(T1, h, s1, Ch, sha512_k[j], W[j]);
      int64add(T2, s0, Maj);

      int64copy(h, g);
      int64copy(g, f);
      int64copy(f, e);
      int64add(e, d, T1);
      int64copy(d, c);
      int64copy(c, b);
      int64copy(b, a);
      int64add(a, T1, T2);
    }
    int64add(H[0], H[0], a);
    int64add(H[1], H[1], b);
    int64add(H[2], H[2], c);
    int64add(H[3], H[3], d);
    int64add(H[4], H[4], e);
    int64add(H[5], H[5], f);
    int64add(H[6], H[6], g);
    int64add(H[7], H[7], h);
  }
  
  //represent the hash as an array of 32-bit dwords
  var hash = new Array(16);
  for(i=0; i<8; i++)
  {
    hash[2*i] = H[i].h;
    hash[2*i + 1] = H[i].l;
  }
  return hash;
}

//A constructor for 64-bit numbers
function int64(h, l)
{
  this.h = h;
  this.l = l;
  this.toString = int64toString;
}

//Copies src into dst, assuming both are 64-bit numbers
function int64copy(dst, src)
{
  dst.h = src.h;
  dst.l = src.l;
}

//Converts a 64-bit number to a hex string. For debugging purposes only.
function int64toString()
{
  var alphabet = new Array("0", "1", "2", "3", "4", "5", "6", "7",
    "8", "9", "A", "B", "C", "D", "E", "F");
  var hs = "", ls = "";
  var i;
  for(i=1; i<=8; i++)
  {
    hs += alphabet[(this.h >>> (32 - (i << 2))) & 0xf];
    ls += alphabet[(this.l >>> (32 - (i << 2))) & 0xf];
  }
  return hs + ls;
}

//Right-rotates a 64-bit number by shift
//Won't handle cases of shift>=32
//The function revrrot() is for that
function int64rrot(dst, x, shift)
{
    dst.l = (x.l >>> shift) | (x.h << (32-shift));
    dst.h = (x.h >>> shift) | (x.l << (32-shift));
}

//Reverses the dwords of the source and then rotates right by shift.
//This is equivalent to rotation by 32+shift
function int64revrrot(dst, x, shift)
{
    dst.l = (x.h >>> shift) | (x.l << (32-shift));
    dst.h = (x.l >>> shift) | (x.h << (32-shift));
}

//Bitwise-shifts right a 64-bit number by shift
//Won't handle shift>=32, but it's never needed in SHA512
function int64shr(dst, x, shift)
{
    dst.l = (x.l >>> shift) | (x.h << (32-shift));
    dst.h = (x.h >>> shift);
}

//Adds two 64-bit numbers
//Like the original implementation, does not rely on 32-bit operations
function int64add(dst, x, y)
{
   var w0 = (x.l & 0xffff) + (y.l & 0xffff);
   var w1 = (x.l >>> 16) + (y.l >>> 16) + (w0 >>> 16);
   var w2 = (x.h & 0xffff) + (y.h & 0xffff) + (w1 >>> 16);
   var w3 = (x.h >>> 16) + (y.h >>> 16) + (w2 >>> 16);
   dst.l = (w0 & 0xffff) | (w1 << 16);
   dst.h = (w2 & 0xffff) | (w3 << 16);
}

//Same, except with 4 addends. Works faster than adding them one by one.
function int64add4(dst, a, b, c, d)
{
   var w0 = (a.l & 0xffff) + (b.l & 0xffff) + (c.l & 0xffff) + (d.l & 0xffff);
   var w1 = (a.l >>> 16) + (b.l >>> 16) + (c.l >>> 16) + (d.l >>> 16) + (w0 >>> 16);
   var w2 = (a.h & 0xffff) + (b.h & 0xffff) + (c.h & 0xffff) + (d.h & 0xffff) + (w1 >>> 16);
   var w3 = (a.h >>> 16) + (b.h >>> 16) + (c.h >>> 16) + (d.h >>> 16) + (w2 >>> 16);
   dst.l = (w0 & 0xffff) | (w1 << 16);
   dst.h = (w2 & 0xffff) | (w3 << 16);
}

//Same, except with 5 addends
function int64add5(dst, a, b, c, d, e)
{
   var w0 = (a.l & 0xffff) + (b.l & 0xffff) + (c.l & 0xffff) + (d.l & 0xffff) + (e.l & 0xffff);
   var w1 = (a.l >>> 16) + (b.l >>> 16) + (c.l >>> 16) + (d.l >>> 16) + (e.l >>> 16) + (w0 >>> 16);
   var w2 = (a.h & 0xffff) + (b.h & 0xffff) + (c.h & 0xffff) + (d.h & 0xffff) + (e.h & 0xffff) + (w1 >>> 16);
   var w3 = (a.h >>> 16) + (b.h >>> 16) + (c.h >>> 16) + (d.h >>> 16) + (e.h >>> 16) + (w2 >>> 16);
   dst.l = (w0 & 0xffff) | (w1 << 16);
   dst.h = (w2 & 0xffff) | (w3 << 16);
}

//Converts an 8-bit or 16-bit string to an array of big-endian 32-bit dwords.
//In 8-bit function, characters >255 have their hi-byte silently ignored.
function str2binb(str)
{
  var bin = Array();
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < str.length * chrsz; i += chrsz)
    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (32 - chrsz - i%32);
  return bin;
}

//Converts an array of big-endian dwords to a string
function binb2str(bin)
{
  var str = "";
  var mask = (1 << chrsz) - 1;
  for(var i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCode((bin[i>>5] >>> (32 - chrsz - i%32)) & mask);
  return str;
}


//Converts an array of big-endian dwords to a hex string.
function binb2hex(binarray)
{
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i++)
  {
    str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +
           hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8  )) & 0xF);
  }
  return str;
}

//Convert an array of big-endian dwords to a base-64 string
function binb2b64(binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var str = "";
  for(var i = 0; i < binarray.length * 4; i += 3)
  {
    var triplet = (((binarray[i   >> 2] >> 8 * (3 -  i   %4)) & 0xFF) << 16)
                | (((binarray[i+1 >> 2] >> 8 * (3 - (i+1)%4)) & 0xFF) << 8 )
                |  ((binarray[i+2 >> 2] >> 8 * (3 - (i+2)%4)) & 0xFF);
    for(var j = 0; j < 4; j++)
    {
      if(i * 8 + j * 6 > binarray.length * 32) str += b64pad;
      else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
    }
  }
  return str;
}
